A. Field of the Invention
This invention relates to an improvement in the manufacture of roll-in pastry shortening and more particularly to an improvement in the production of the pastry shortening used in making roll-in pastry dough products such as puff pastry and danish pastry.
B. Description of the Prior Art
Roll-in pastries, such as puff pastry (sometimes referred to as French pastry) and danish pastry, are made from a laminated dough sheet consisting of a great many very thin alternate layers of shortening and dough.
Puff pastry and danish pastry are discussed in Bakery Technology and Engineering, S. A. Matz, Editor (1960), at pages 304 to 306 and pages 258 to 259, respectively. The preparations of puff pastry and danish pastry have been similar insofar as layers of fat are interleaved between layers of dough, so that upon baking a separation of dough strata occurs. Puff pastry ingredients usually include no leavening, but, in spite of this, puff pastry baked products have an open network of crisp and flaky layers. In danish pastry, however, yeast leavening and auxiliary ingredients produce a baked product having a soft and porous structure in the dough layers.
In a conventional method of making danish-type pastry goods, a yeast leavened dough is rolled into an approximately square sheet, and beginning at one end of the sheet a layer of fats is spread on approximately two-thirds of the sheet surface. The untreated third is then folded over the middle treated portion, and the remaining one-third which has been covered with fat is folded on top of the untreated surface. The folded dough is then rolled again to produce a sheet consisting of three layers of dough separated by two layers of fat. The dough is then sheeted again and folded as before, and the folding steps are continued for a number of times. The final laminated sheet is then shaped into coffee cakes, rolls and the like.
Puff pastry has been conventionally made in a manner similar to danish pastry, except, as mentioned above, the puff pastry is not usually leavened. In a so-called rapid puff pastry method a dough ball is formed from ingredients including fat, flour, salt and water; and then a large quantity of roll-in fat is "blitzed" into the dough ball. In the "blitz" method the fat is not spread on the dough. Further background on the nature of puff pastry products can be found in the article entitled, "Treatise on Puff Pastry", bulletin Rm-172 dated Oct. 20, 1968, published by The Associated Retail Bakers of America, 735 West Sheridan Road, Chicago, Illinois, and the publication entitled, "Sweet Doughs & Pastry", published by The American Institute of Baking, Chicago, Illinois, in 1968 (3rd. Revision).
The rheological characteristics of the shortening used in the preparation of puff pastry is quite critical because the desired puff pastry product is a treated flaky base product with definite separation of the dough layers. The puff pastry itself contains flour, shortening, salt and water. Shortening is used in the dough itself and as a roll-in additive between the layers of dough. The preparation of the puff pastry itself involves three basic steps: preparation of the dough, incorporation of the roll-in fat and the folding and sheeting operation. The dough preparation and folding and sheeting steps develop the gluten in the flour.
These procedures are designed to optimize the gluten development for maximum expansion upon baking. During the folding and sheeting operations which are usually conducted at room temperature, the puff pastry shortening must be plastic and tough so as to spread into a thin, uniform film between the layers of dough without either soaking into the dough or tearing the dough. Furthermore, the finished puff pastry product must have good "mouth feel"; so the shortening should have a rather sharp melting characteristic in the vicinity of body temperature.
Puff pastry shortening must be capable of being spread into uniform layers when compressed between layers of dough. This requirement means that the dough should have certain toughness or elastic stress-strain characteristics within the normal room temperatures encountered. Storage of pastry shortening may be in the range of 50.degree. to 90.degree. F. while the temperature of actual use is about 70.degree. to 75.degree. F. If the pastry shortening is too firm or too hard when used, it will tear holes in the dough and cause discontinuities when the dough is folded. If the shortening is too soft, the shortening has a tendency to "oil out" or soak into the dough rather than remaining as a distinct layer between the two layers of dough. Since shortening is used directly from storage, the shortening should have a wide temperature range of usefulness.
In other words, the shortening should possess ideally the unique combination of properties wherein it is tough yet plastic over a wide temperature range of 50.degree. to 90.degree. F. while maintaining its structure and consistency when worked repeatedly and produce a light flaky pastry upon baking. In the baking arts, this is referred to as a "functionality"; so the shortening should be "functional" over the temperature range of 50.degree. to 90.degree. F. Furthermore, the shortening should have a low enough melting point to provide a good mouth feel to the finished baked product rather than the waxiness or greasy mouth feel associated with the high-melting fats.
In the past, pastry shortenings have been functional over very narrow ranges of temperatures. In fact, it is not an uncommon requirement that the shortenings be brought to a specific temperature (say 70.degree. to 75.degree. F.) before rolling into the dough. This means that the pastry shortening must be brought to the use temperature when the temperature of storage is different from the temperature of use. The achievement of even these rather narrow temperature ranges of functionality has been only after tempering the finished shortening for several hours or even several days to achieve the crystalline structure necessary for shortening functionality.
Accordingly, the present invention provides a continuous process for forming an untempered functional pastry shortening having functionality for roll-in pastry applications over a temperature range of 50.degree. to 90.degree. F. while providing good mouth feel in the finished baked product. As used herein the term "untempered" means that the pastry shortening is not subjected to a prolonged additional thermal treatment to develop and stabilize the crystalline phases after the shortening is "filled" or extruded into user packages.